11/45 hack?

Jacob Ritorto jacob.ritorto at gmail.com
Sat Feb 7 12:46:04 CST 2015


Hi,
  Man. I'm becoming concerned that I can't fit any of the significant
features that I want in my 11/45 without making uncomfortable sacrifices.

  The first 25 slots are for an initial "unibus a" terminator, cpu,
floating point and memory, which, since I only have one bipolar matrix, is
an enormous waste of like ten slots (they're wired for weird voltage and
would presumably explode other boards installed there, right?).

  So then there are three slots available at the end, 26, 27, 28 that are
also marked "non-standard voltage."  I guess that means that putting normal
boards in there is right out, too.  Anyway, the unibus out and bridge 9200
jumper that connects unibus a and unibus b are supposed to go there.
That's it for the main backplane.

  The next three small backplanes are core.  They take up the rest of the
chassis.  I don't want to give up my core because core is cool, right?

  So this means I've nowhere to put the hex boards I need to run.

  I need to install more memory (planning to use MS11 (124KW M7891)),
ethernet, some sort of hex height SMD disk controller (SC21,etc.), possibly
an RL11, and a DZ11.  That's at least four, maybe six hex-height boards I
need to accommodate.

  I'm going to duck after asking this, but would it be at all feasible to
rewire the main 11/45 backplane to get rid of the weird voltages in those
bipolar slots so they'd accommodate normal boards like these?

  Short of that, what can I do?  I definitely don't want another chassis.
I guess I have to sacrifice my core to make way for a second "normal"
dd11-type backplane to house the modules I need to run.  So sad.


<duck>
jake


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